1. Field of the Invention
The present invention relates to an air conditioner that prevents dew formation and adherence of stains having various properties, on/to resin-made components installed to a rear flow side of the heat exchanger, both at the same time, during the cooling operation. Also, the present invention relates to a coating composition that can provide either one of an antifouling property or a hydrophilic property to the coating resin thereon.
2. Description of the Related Art
In the air conditioner that conditions the air inside a room by blowing out the cool air, during the cooling operation, a casing unit (forms an airflow route) and louvers at a periphery of the outlet vent are cooled down below a dew-point temperature of the indoor air surrounding the air conditioner by the cool air blown out. For this reason, the condensation occurs, and when the cooling operation continues for a long time, the condensate water enlarges into a large droplet, which eventually drips down to make a floor wet. Even if the dew does not drip, when the droplet is retained there and not dried for a long time, a black or blue mold may grow by taking nutrients from the stains that became adhered by collision of the air. Bad odors are generated therefrom, and mold spores are released inside the room.
In order to prevent the dew formation on the resin-made components placed in the airflow route of this air conditioner, for example, the patent document 1 discusses the coating of the periphery of the outlet vent of the main body with a paint having the hydrophilic property, for promoting shifting of the condensate water by weakening its surface tension.
Moreover, the patent document 2 discusses the coating with a paint having the hygroscopic property by blending zeolite of 5% by mass into an acryl emulsion type paint, which is a paint having the hygroscopic property, thereby preventing the condensation.
There are other methods such as absorbing of the condensate water adhered to filaments pasted near the outlet vent and the casing unit, and depriving temperature difference by pasting a heat insulating material.
These conventional approaches of the dew prevention, however, are coating with the paints having the hydrophilic property and the hygroscopic property. Although a certain effect of restraining the droplet enlargement is observed to some extent, however, when the airborne particles inside the room sucked in by the ventilation fan, such as dusts and sands, collide to wall faces of the high-speed components in a vicinity of the casing unit and the outlet vent, because their surfaces are hydrophilic, the stain having the hydrophilic property is easily adhered. When the stains accumulate, the stains are retained together with the condensed moisture, making them difficult to evaporate. There is an increased risk of preparing an environment ideal for the mold growth, nutrients such as the stains, moisture, air and high humidity. Accordingly, macroscopically, there is a need for a way to provide a method of preventing adherence of various stains having amphiphilic properties, at the same time as restraining the droplet enlargement by utilizing the hydrophilic property.
For example, the patent documents 3 and 4 discuss various measures for restraining various stains, such as powders, dusts, greasy fumes, tar of cigarette, and the like, that cohere on the surfaces of various products used either indoor or outdoor. For example, the patent documents 3 and 4 discuss prevention and easy removal of stains having an oilphilic property by coating the product surface with an oil-repellant fluororesin or an antistatic agent. In the coating employed to the air conditioner, in order to prevent a droplet bridge formation to the heat exchanger, the coating composition having the antifouling property microscopically disperses an optical catalytic oxide and a water-repellant fluororesin, and the applied surface is exposed to come in contact with the outside air, and a contact angle θ formed by the film surface and water is made 90 degrees or above.    [Patent Document 1] Japanese Published Patent Application No. 4-344032    [Patent Document 2] Japanese Published Patent Application No. 8-247526    [Patent Document 3] Japanese Published Patent Application No. 10-132483    [Patent Document 4] Japanese Published Patent Application No. 10-47890.